A Waveform Display Synchronization Method in Multi-channel Digital Three-Dimensional Oscilloscope

As the signal frequency increases, the signal timing margin decreases sharply. Moreover, some accidental signals should be captured for circuit debugging. Thus, high-performance measuring instruments are urgently needed. A digital oscilloscope is the most commonly used time-domain test instrument. On one hand, the capture capability of oscilloscope depends on its signal processing speed and waveform display method. The processing speed of traditional digital oscilloscope is slow because of its serial process method. The sample data storage is stopped when sample data are processed. If an accidental signal occurs at this moment, it cannot be captured. Therefore, the process time is named dead time. To reduce dead time, digital three-dimensional oscilloscope (DTO), which owns fast signal processing capability and three-dimensional waveform display effect, is proposed. On the other hand, DTO is a multi-channel acquisition system. The timing difference of data storage and waveform processing in the multi-channel system appears. It leads to extra delay between different channels. It is called multi-channel synchronization problem. In this paper, the mathematical model of acquisition and display system in multi-channel DTO is constructed. Furthermore, the synchronization problem in the proposed low cost multi-channel DTO is researched. The synchronization method is proposed and validated. The result shows that the extra delay between different channels is eliminated. The proposed multi-channel DTO can help engineers capture accidental signals more easily.